Valve



Feb. 15', 1944. M. v. FRIEDELL VALVE Filed May 20, 1943 l/ genre/44914;@JAP WMM v .4 Y,

Patented Feb. 15, 1944 UNITED STATES PATENT OFFICE VALVE Morley V.Fr'iedell, El Cerrito, Calif.

ApplicationMay 20, 1943, Serial No. 437,785 v 2 Claims.

This invention, a highly efficient, noiseless valve, is designed toovercome many of the deciencies and faults of conventional types ofvalves, particularly those used in connection with gas transfer devices,such as compressors and vacuum pumps, and particularly such as operateunder impulse, including reciprocating and oscillating compressors,pumps, and blowers.r

Air compressors and vacuum pumps, and gas compressors for refrigeratingsystems usually require a comparatively slight valve opening or liftwhen operating under normal intake and back pressures or when operatingunder normal intake pressure against an existent high pressure, butrequire a considerably greater opening or lift when the intake pressureis above normal or the back pressure is below normal.

For instance: In refrigerating systems the'liquid gradually expands toits gaseous form with direct access to the intake of the compressor,creating a positive pressure at the intake. Under normal conditions thecompressor recompresses the gas before there is any appreciable build-upof the positive pressure, and While the back pressure from thepreviously compressed and liquied gas is substantially normal. This isthe condition which requires the minimum lift of the valve.

When the compressor is started for'the first time in a new unit, orafter the system has been defrosted, this positive pressure at theintake may readily reach a value of four or ve times normal while theback pressure may be reduced.

Obviously, with this high intake pressure, the volume of free gasavailable per cycle of the compressor may be anywhere up to five or moretimes normal, and since the compressor will be operating against anormal to W back pressure, the valve will be the sole restrictionagainst delivery of the gas from the compressor. Under such conditions,with a valve lift adjusted for normal intake and normal back pressures,the internal back pressure of the compressor will be extremely high,causing heating of the compressor and consequent delivery of thecompressed gas at a comparatively high temperature, with resultantincreased power demand and possible detrimental effects on both, thecompressor and its prime mover, and, decreased eliciency throughout theentire system.

If suflcient valve opening or lift is provided to compensate for allconditions of operation (and which is the conventional procedure), theeinciency of the compressor and the entire system will be impaired andvalve noise will lie-considerably increased-conditions which are r`by nomeans desirable.

Furthermore, when air or gas is being pumped against a high backpressure requiring only a slight valve lift,the requirement-,may besuddenly and greatly increased if either oil or Water must pass throughthe valve opening along with the gas. If the opening is insucient,knocking. or hammering is certain to occur, and the compressor or pumpmight be damaged or even wrecked by the impact. For this-reason it iscusi tomary to allow a considerably greater valve lift than is normallyrequired, and this increased valve lift results in valve clatter withconsequent rapid deterioration of the valve and its seat.

This invention provides a valve which operates automatically to restrictthe valve for normal conditions and to compensate for variations inintake pressure, back pressure, and for any oil or water slugs which mayform -for delivery along with the air or gas. The valve is noiseless inoperation, seats perfectly Without requiring axial alignment of thevalve and its seat whenA using the spherical type of valve, though thesame principle may be applied tothe conventional mushroom type or thedisc type valve. However, the spherical type of valve is preferredbecause of its seating eiciency and longer life.

The objects and advantages of the invention are as follows:

First, to provide a noiseless valve for air and gas compressors andpumps, and other related devices.

Second, to provide a valve which will automatically compensate forvariations in pressures and volumes of gases at intake and delivery, asalso for the existent back pressure, and for liquids which might beincluded in the delivery with the gas, such as oil or water.

Third, to provide a valve as outlined preferably of the spherical-typewhich will seat perfectly even when the valve is not axially alignedwith its seat.

Fourth, to provide a valve'as outlined which under normal operatingconditions will provide the minimum necessary opening for ecientdischarge coupled with rapid closure when the gas has been discharged,and which will automatically increase the opening .for passage of thegas under conditions of high intake pressure or low external backpressure and to pass any liquids which might be incorporated with thegas being delivered through the valve opening.

Other objects and advantages of the invention W-ill become apparent asthe following description is read on the accompanying drawing, in which:

Fig. 1 is a top plan view of the invention.

Fig. 2 is a vertical section through the invention.

Fig. 3 is a section taken on line 3--3 of Fig. 2.

Fig. 4 is a section taken on line 4--4 of Fig. 2.

Fig. 5 is a fragmentary sectional elevation showing a conventionalmushroom type valve substituted for the preferred spherical type.

Fig. 6- is a fragmentary sectional elevation showing another modicationemploying the conventional disc type valve.

The invention comprises a valve casing including a cap member Ill and abase member II and the assembly of operable and adjustable elementsincorporated therein.

The cap member is cylindrical and provided With external threads at oneend I2 and with the other end I3 reduced in diameter to flt respectivelyin a threaded bore I4 and the smaller cylindrical extension I5 formed inthe pump or compressor structure I6. This cap member has a head I1provided with a circular series of combinedair passages and spannerwrench sockets I8 and an axial threaded bore I9.

The base member I I is also cylindrical with a diameter preferably equalto that of the reduced portion of the cap member and has a bore 20terminating in a valveyseat 2|, providing a. replaceable valve seatwhich can be easily removed and replaced in case of'wear or damage.

The valve adjusting stem 22 is threaded as shown and provided withadjusting and locking means, such as the screwdriver slot 23 and locknut 24, and terminates at its lower end inl a collar 25, and anaxialbore 26 to function as a spring socket is formed in the lower end.

Slidably mountedvon the valve adjusting stem 22 is a valve stop l21which has a counterbore 28 slidably fitting the collar 25 and seating onthe top face thereof, and having a base 29 with a diameter substantiallyequal to the diameter of the valve, with grooves 30 formed radially tobreak suction and adhesion between the valve and the'base 29, thoughserrations or passages could be substituted for these grooves.

The upper end of this stop is considerably reduced in diameter andterminates at its lower end in a spring seat 3|. A spring thrust collar32 is threadedly mounted on the valve adjusting stem as shown and isrelatively adjustable for controlling the urgence of the compressionspring 33 and to limit the maximum lift of the valve, and a suitablelocknut 3ft is provided for locking the collar 32 in its adjustedposition.

The Valve 35 is spherical and seats on the valve seat 2l in any relativeposition, is internally hollowed for lightness, and has a spring pilot36 on which the spring 31 is resiliently secured and which spring ishoused in the spring pocket 26 in the valve adjusting stem 22 and seatsagainst the bottom 33 of this pocket or bore.

The spring pilot 36 and the spring 31 are both appreciably smaller indiameter than the bore 26, which allows the valve to find a perfect seatWithout frictional or axial restrictions. The spring 31 has`comparatively light tension, just enough t0 urge rapid seating of thevalve without creating unnecessary back pressure. To create rapidseating with minimum back pressure, the valve is internally hollowed tomake it as light as possible, and the normal lift of the valve indicatedat 39 is iixed at an absolute minimum for the normal volume of gas to bepassed against a normal back pressure. This lift, governed by the volumeof gas to be discharged with each impulse, the pressure against whichthe gas is normally discharged, and the size of the valve, may be aslittle as .002 inch, and it seldom happens that a lift in excess of .015inch is necessary, for which reason the spring 31 can be comparativelylight or of 10W tension, and due to this minimum lift and the lighttension spring, the valve is practically noiseless in operation.

The valve lift is adjusted by means of the valve adjusting stem 22 forthe specific conditions under which the gas is delivered. The lift is aminimum when the gas is discharged against a Vcomparatively high backpressure in conjunction with a comparatively low intake pressure.

With the valve lift adjusted for normal operation, other conditions mustbe compensated for, such as when operation of a compressor or pump isstarted when the discharge is against some low pressure ranging upwardfrom atmospheric, or when the intake pressure is above normal orpositive, and, when water of condensation, or oil used for lubricationor for sealing is deliveredV with the gas through the discharge, ineither of which cases a greater lift must be provided to compensate forthe increased Volume, and this compensation is made through the stopmember 29 and spring 33.

The spring 33 is of somewhat greater tension than the spring 31, withjust sufficient excess tension to resiliently retain the stop memberagainst lifting except when additional valve lift as previously pointedout, is required. The spring thrust collar 32, being adjustable on theadjusting stem, can be adjusted to limit the lift of the stop member toany desired maximum required to compensate for any abnormal conditions.This resiliently held stop member is in the main responsible for thequiet operation of the valve, because the valve, when lifting, does notimpact against a rigid, immovable stop, but against a resiliently heldstop which gives under impact and thereby absorbs any resultant shock,and to the cushioning effect of the oil between the contacting surfacesof valve and stop, and the absorption of the valves inertia by thespring 33. It permits of a greater valve lift with noiseless operation.

The operation of the valve is as follows: When operating normally, thecompressor or pump will discharge against some predetermined pressure,herein referred to as back pressure. The valve is adjusted for thatspecific back pressure, and the valve under such conditions lifts tocontact the stop member against the urgence of the spring 31 when thegas is being delivered through the Valve passage against thatpredetermined pressure. If there is a sudden lift of the valve, it willreact on the stop member lifting it slightly to absorb the shock,coupled with immediate rebound. If a slug of oil or other liquid isdischarged along with the gas, more space will be required between thevalve and its seat to pass the liquid, lifting the stop member againstthe urgence of the heavier spring 33 to whatever extent is necessary topass the liquid, up to the limit deiined by the thrust collar 32.

The same applies when the compressor is started against a pressureappreciably below normal when the volume of the discharging gas isgreater, or when the intake pressure is above normal as in the case ofrefrigeration following defrosting which results in a greater intakevolume in terms of free gas. Thus the valve operates at highestefficiency for normal operating conditions andl compensates for anyvariations in back pressure, intake pressure, thermal variations, andvapors or liquids to be passed along with the gas.

The modication illustrated in Fig. is similar in all respects to thepreferred form in Figs. 1 to 4 with the exception that a mushroom typeof valve is substituted for the spherical type, and this mushroom typeof valve must seat accurately and axially if a perfect seal is toresult, therefore the valve must have an `axial stem 40 which isslidable in the axial bore 2t'.

The modication illustrated in Fig. 6 is also similar in all respectswith the exception that the disc type of valve is shown, and for thistype of valve it is necessary to project the stop member 29 below thebottom of the collar 25 as indicated at 4|, and a flat seat |32 isrequired for proper seating of the disc 43. l

It Will be understood that variations in construction and arrangement ofparts, which Variations are consistent with the appended claims, may beresorted to Without detracting from the spirit or scope of theinvention, or sacrificing any of the advantages thereof.

I claim:

l. A Valve comprising; a cap member having a head provided with an axialthreaded passage and with air passages; a base member having a centralpassage and a valve seat; a valve seated on said seat and a compressionspring attached at one end centrally of said valve and functioning as avalve stem and as resilient urging means to seat said valve; anadjustable member adjustable in said threaded passage and havingr at oneend a bore for freely supporting said spring and terminating in a seatfor the other end'of said spring, and a collar formed at said one end ofthe adjustable member; a stop member slidably mounted on said adjustablemember and cooperating with said collar to limit the movement of saidstop member toward said valve, and a second compression spring urgingsaid stop member against said collar and a seat adjustable on saidadjustable member for said second spring, whereby said valve mayincrease its normal lift under other than normal operating conditions byovercoming the urgence of said second spring and lifting said stopmember.

2. A valve cap having an axial threaded passage and an adjusting membermounted in said passage having adjusting means at one end and a collarand an axial spring socket formed at the end; a spherical valve and aseat therefor; a compression spring attached centrally of said valve andhoused in said socket and functioning as a valve stem and as valveurging means; a stop member slidable on said adjusting member andseating on said collar; a spring seat member adjustable on saidadjusting member and a second -compression spring cooperating betweensaid spring seat member and said stop member.

MORLEY V. FRIEDELL.

